New Palladium Complexes Containing Methyl Gallate and Octyl Gallate: Effect against IMycobacterium tuberculosis/I and ICampylobacter jejuni/I

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 9
• Main Authors: Silva, Raphael Tristão Cruvinel, Guidotti-Takeuchi, Micaela, Peixoto, Jéssica Laura Miranda, Demarqui, Fernanda Manaia, Mori, Ananda Paula, Dumont, Carolyne Ferreira, Ferreira, Gabriella Rayane Aparecida, Pereira, Gabriele de Menezes, Rossi, Daise Aparecida, Corbi, Pedro Paulo, Pavan, Fernando Rogério, Rezende Júnior, Celso de Oliveira, Melo, Roberta Torres de, Guerra, Wendell
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-05-2023
• Subjects: Palladium; Sparfloxacin; Tetracycline; Tetracyclines; Tuberculosis; Brazil
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28093887

This work describes the preparation, characterization and antimicrobial activity of four palladium(II) complexes, namely, [Pd(meg)(1,10-phen)] 1, [Pd(meg)(PPh[sub.3])[sub.2]] 2, [Pd(og)(1,10-phen)] 3 and [Pd(og)(PPh[sub.3])[sub.2]] 4, where meg = methyl gallate, og = octyl gallate, 1,10-phen = 1,10-phenanthroline and PPh[sub.3] = triphenylphosphine. As to the chemical structures, spectral and physicochemical studies of 1-4 indicated that methyl or octyl gallate coordinates a palladium(II) ion through two oxygen atoms upon deprotonation. A chelating bidentate phenanthroline or two triphenylphosphine molecules complete the coordination sphere of palladium(II) ion, depending on the complex. The metal complexes were tested against the Mycobacterium tuberculosis H37Rv strain and 2 exhibited high activity (MIC = 3.28 μg/mL). As to the tests with Campylobacter jejuni, complex 1 showed a significant effect in reducing bacterial population (greater than 7 log CFU) in planktonic forms, as well as in the biomass intensity (IBF: 0.87) when compared to peracetic acid (IBF: 1.11) at a concentration of 400 μg/mL. The effect provided by these complexes has specificity according to the target microorganism and represent a promising alternative for the control of microorganisms of public health importance.